1. Field of the Invention
The present invention relates to a lens cap unit used for imaging apparatuses such as digital cameras and so on.
2. Description of the Related Art
In a conventional imaging apparatus such as a digital still camera or digital video camera (hereinafter, referred to as digital camera), a lens barrel is used in which a movable lens cylinder to hold at least one lens is provided inside a fixed cylinder, and the movable lens cylinder is extended from the fixed cylinder and collapsed in the fixed cylinder. In such a lens barrel, it is known to protect a lens or lenses arranged in the lens barrel, in particular, the movable lens cylinder by mounting a lens cap on the fixed cylinder when the movable lens cylinder is collapsed in the fixed cylinder.
In such a lens cap, it is considered that an annular mounting part fixed to the fixed cylinder and at least one barrier rotatably provided on the mounting part to cover a leading end of the movable lens cylinder at an inner side of the mounting part are provided (for example, JP2009-258600). In the lens cap, when the movable lens cylinder is extended from the fixed cylinder, a back surface of the barrier is pressed by the leading end of the movable lens cylinder, and thereby the barrier is in an opening state. In addition, in the lens cap, when the movable lens cylinder is contained in the fixed cylinder, because the back surface of the barrier is not pressed by the leading end of the movable lens cylinder, the barrier is in a closed state. Because the barrier can be opened and closed in a state where the lens cap is attached to the fixed cylinder, it is not necessary for a user to attach the lens cap to the fixed cylinder and to detach from the fixed cylinder. Therefore, a high usability is accomplished.
However, in the lens cap as mentioned above, because the back surface of the barrier is pressed by the leading end portion of the movable lens cylinder, thereby the barrier is opened, if the lens cap is applied to a lens barrel configured to extend with a small extended amount from the fixed cylinder, there is a possibility that the barrier cannot be sufficiently opened.